Cushioning and insulating material



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BY Y I 1968 M. A. CHAVANNES CUSHIONING AND INSULATING MATERIAL OriginalFiled Sept.

1968 M. A. CHAVANNES 3,4

CUSHIONING AND INSULATING MATERIAL Original Filed Sept. 10, 1963 2Sheets-Sheet 2 nbvENToR. A/Awc A. 67/4 VAN/V55 ATTORNEY United StatesPatent 3,415,711 CUSHIONING AND INSULATING MATERIAL Marc A. Chavannes,Fort Lee, N.J., assignor to Sealed Air Corporation, Hawthorne, N.J., acorporation of New Jersey Original appiication Sept. 10, 1963, Ser. No.307,966, now Patent No. 3,346,438, dated Oct. 10, 1967. Divided and thisapplication Apr. 20, 1967, Ser. No. 647,268

3 Claims. (Cl. 16168) ABSTRACT OF THE DISCLOSURE An improved cushioningand insulating material formed of at least two layers of plasticmaterial, at least one of which has sealed embossments extending fromthe surface thereof with the side walls of adjoining embossments beingjoined one to the others.

This application is a division of United States Patent No. 3,346,438,issued Oct. 10, 1967, entitled Method and Apparatus for MakingCushioning and Insulating Material.

This invention relates to composite cushioning and insulating materialsand more specifically concerns a new and improved cushioning materialand the method and apparatus for the manufacture thereof.

Insulating and cushioning materials made of a variety of plastics arenormally fabricated of two layers, at least one of which is providedwith a plurality of embossments forming sealed pockets within thematerial. These pockets are necessarily arranged in spaced relationshipone to the others with the result that any individual pocket may bestressed independently of the surrounding pockets. In instances whereinthe material is used as an insulating element, the areas between thepockets do not afford the insulating characteristics of the areascontaining pockets. This invention overcomes these difiiculties andprovides a material affording both improved cushioning as well asinsulating characteristics.

Another object of this invention resides in a new and improved methodand apparatus for manufacture of cushioning materials, having improvedcushioning and insulating characteristics.

Another object of this invention embraces the provision of a new andimproved method and apparatus for manufacture of cushioning materialswherein wall po-rtions of individual cells are sealed one to another forgreater strength.

Still another object of this invention resides in the provision of a newand improved plastic cushioning material wherein a plurality ofhermetically sealed air pockets are joined one to the others to form ineffect a sealed honeycomb structure.

Another object of the invention resides in the provision of a new andimproved method and apparatus for the manufacture of cushioningmaterials wherein the wall portions of the individual cells extendoutwardly toand in close proximity to the walls of the adjoining cells.

A further object of this invention resides in a new and improvedmaterial wherein the top surfaces of embossments provide a substantiallycontinuous surface in generally parallel relationship to the layersealing the embossments.

A still further object of this invention resides in the provision of anew and improved cushioning material wherein a plurality of embossmentsare joined one to the others to form a relatively homogenous cellularstructure.

The above and other objects and advantages of this invention will becomemore apparent from the following ice description and accompanyingdrawings forming part of this application.

In the drawings:

FIGURE 1 is a diagrammatic illustration of one embodiment of apparatusin accordance with the invention.

FIGURE 2 is an enlarged fragmentary section of the embossing roller ofFIGURE 1 having a portion of embossed material thereon.

FIGURE 3 is an enlarged fragmentary section of the compression rollerand pressure belt of FIGURE 1.

FIGURE 4 is a plan view of the cushioning material with spacedembossments as it is fed onto the compression roller.

FIGURE 5 is a cross-sectional view of FIGURE 4 taken along the line 55thereof.

FIGUREE 6 is a plan view of the improved cushioning material inaccordance with the invention.

FIGURE 7 is a cross section of the material shown in FIGURE 6 takenalong the line 7-7 thereof.

FIGURES 8 and 9 are cross-sectional views along the lines of FIGURE 7and showing modified forms of the improved cushioning material inaccordance with the invention.

The improved material in accordance with the invention embodies at leasttwo layers of a. plastic material fused one to the other with at leastone of the layers having discrete embossments extending from one sidethereof and in closely spaced relationship. The side walls of eachembossment are fused to the side walls of adjoining embossments so thatthe completed material affords the effect of a pair of spaced layers ofplastic having a honeycomb of air cells incorporated therebetween. Withthis arrangement, each air cell or embossment is laterally supported bythe surrounding embossments and as a result a substantially stronger,more durable cushioning material is obtained. Furthermore, by theelimination of the spaces between the adjoining embossments, theinsulating qualities of the material are substantially improved, andthere are no cracks or crevasses for the accumulation or collection offoreign matter.

While the material as described above may be fabricated in a variety ofmodes, one method and apparatus is illustrated in FIGURES 1 to 3. Inthese figures, the two layers of plastic material, which may be sheetsof a homogenous material or may comprise previously laminated sheets ofplastic materials having different properties, are generally denoted bythe numerals 10 and 11. One procedure for preheating the layers 10 and11 prior to treatment in accordance with the invention is disclosed in aprior application for US. patent entitled Method and Apparatus forMaking Laminated Cushioning Material and the Resultant Products, Ser.No. 855,712, filed Nov. 27, 1959, now United States Patent No.3,142,599, granted July 28, 1964. In the event the layers are extrudedimmediately prior to embossment and lamination in accordance with thisinvention, it may be desirable to lower the temperature of the extrudedlayers so that they will have the proper embossing and laminatingtemperatures to effect the desired result.

The layer or lamina 10 is fed onto the embossing roller 12 by means ofthe roller 13, which if necessary can 'be heated to raise or at leastmaintain the temperature of the'layer 10 at its embossing and laminatingtemperature. The lamina 10 is embossed by roller 12 which preferablyincludes vacuum means for creating a plurality of closely spaceddepressions. The second lamina or layer 11 is fed onto the surface ofthe embossing roller 12 and in overlying relationship to lamina 10 byroller 15, which, similar to roller 13, may be provided with heatingelements to raise or at least maintain the temperature of lamina 11 atits fusing temperature. Roller 15 may be arranged to exert a slightpressure against the two laminae and 11 as they are brought intooverlying relationship at 16, though in most applications utilizing thinplastic layers, the roller 15 need not be in pressure contact with thelayers 10 and 11. The lamina 11 is hermetically fused to the unembossedportions of lamina 1(9, hermetically sealing the embossments 17 whichare clearly visible in the laminate 18 as it is stripped from theembossing roller 12 by stripping roller 19.

A magnified partial cross section of the embossing roller is shown inFIGURE 2, having a portion of the laminated material 18 thereon.Although the embossing depressions 20 in the surface of the embossingroller 12 are shown to have cylindrical configurations, it isunderstood, of course, that these depressions could be of a differentsize and shape, such as may be used, for example, in connection with theforming of hexagonal embossments. The embossing roller 12 is providedwith central vacuum means from which a plurality of passages 22communicate with each embossing depression 20. By means of this vacuum,the soft lamina 10 is drawn into the depressions during the process ofembossing. The surface area of the embossing roller 12 surrounding thedepressions 20 may carry an adhesion-resisting layer 23 of silicone orother similar material. These coated surfaces prevent the heated lamina10 from adhering to the roller 12 as the lamina is molded andsubsequently fused with lamina 11 at 16.

Stripping roller 19 removes the embossed cushioning material 18 from theroller 12 after the material has been cooled to complete the sealingprocedure. The material 18 is then conveyed through an oven 24 having aradiant heater 25 for heating at least the surface of the embossments 17to a temperature in the vicinity of the melting point of the plasticmaterial. By the use of heat rays of selected wavelength, the majorportion of the heat Will be absorbed by layer 10 and the fluid entrappedin the sealed embossments 17 will receive a minimum quantity of heat,thereby minimizing the expansion of the fluid.

The heated laminate 18, upon leaving the oven 24, is directed about aroller 28 and onto the drum 26. The roller 28 together with thecooperating rollers 28 and 28" carries a belt 27 which rides over thesurface 29 of the drum 26 and constitutes a compression element forcompressing the laminated material 18 as it passes between the belt andthe drum 26. If desirable, radiant the embossments and insure a positiveseal. In this case it is preferable to utilize a perforated belt 27 ofsuitable insulating material. One or more of the rollers 28, 28' and 28"may also be cooled to maintain the desired belt temperature whether itbe metallic or insulating in order to produce a uniform product.

The rollers 28, 28' and 28" are driven at a speed so that the belt 27will have a velocity corresponding to the peripheral velocity of thedrum 26. Since the embossed side of the laminate 18 is heated by theoven 24, when the material is placed under compression, the embossmentsor cells are compressed and the side walls of each cell are urged intocontact with the side walls of adjoining cells and are held until thelaminate is cooled and the seal is effected. For this purpose, it isdesirable to cool the drum or compression cylinder 26.

In some instances it may be desirable to provide means for holding thelaminated material 18 firmly on the compression roller 26, and for thispurpose, a vacuum system maybe employed. Such a vacuum system is shownin FIGURE 3 which constitutes a magnified fragmentary section of theroller 26 and cooperating belt 27. The roller 26 may be provided with acentral vacuum manifold and a plurality of radially disposed tubes 30con nected with the manifold and opening into the surface of the roller.An area of the roller surface surrounding each conduit 30 is preferablyrecessed or serrated as indicated by the numeral 31, and an overlyinglayer of fabric or other porous material 32 is then placed on theperiphery of the roller. In this way, the vacuum from the spacedconduits 30 is distributed throughout the surface of the roller and whenthe laminated structure 18 engages the surface, it is held firmly inplace by the vacuum until the compression operation has been completed.By arranging appropriate valving means such as is shown for instance ina prior patent application, S.N. 13,937, filed Mar. 9, 1960, entitledMethod and Apparatus for Embossing and Laminating Materials, now UnitedStates Patent No. 3,208,898 granted Sept. 28, 1965, the vacuum can beterminated just prior to the point of removal of the finished productfrom the roller 26 by means of the roller 28".

With further reference to FIGURE 3, it will be observed that theembossments in layer 10 are compressed to cause the side walls 10' ofadjoining embossments to firmly contact each other and form an invertedT configuration at the joinder of the layer 10 with the layer 11.Furthermore, the top surface of the layer 10 become substantiallycontinuous and uninterrupted except for minor discontinuities at thejoinder of each set of three cells.

FIGURES 4 through 7 show the steps in the process of fabricating thematerial in accordance with the invention somewhat more clearly. InFIGURE 4, which is a plan view of the embossed material, it will beobserved that the embossments 17 are in closely spaced relationshipthroughout the surface of the laminated structure 18, and while they areshown in circular or cylindrical configuration, it is evident that theembossments could be rectangular, hexagonal or of any other suitableshape. A cross-sectional view of the structure of FIGURE 4 is shown inFIGURE 5. This is an enlarged view which illustrates the generalconfiguration of the embossments 17 and the fusing of the areas betweenthe embossments 17 With the backing layer 11. When the structure shownin FIGURES 4 and 5 is subjected to compressive stress as previouslydescribed, a configuration such as that shown in FIGURES 6 and 7 isobtained. The embossments 17 assume an essentially hexagonalconfiguration since the side walls of each embossment are joined to theadjoining side walls of the surrounding embossments. While all of theembossments are joined firmly with the surrounding embossments, slightdepressions are formed at the corners 17' of each hexagon which givesthe resultant product a slight ripple effect on the embossed surface.This ripple however is very slight, and for all practical purposes, theresultant structure gives the appearance of a pair of spaced layers ofplastic material having cellular-like formations therebetween.

An enlarged cross-sectional view of the structure of FIGURE 6 is shownin FIGURE 7, and it will be seen that the side walls 10' of adjoiningembossments 17 are firmly fused with only a slight depression at thepoint 17.

The improved cushioning material as described above affords a strongerand more durable product since each of the air cells or embossments 17is radially supported by the surrounding embossments, and there is noplace for the accumulation of dirt or other foreign material.Furthermore, by reason of the joinder of the side walls, improvedinsulating characteristics are obtained. The cellular material inaccordance with the invention may also be subjected to further embossingprocesses which makes it particularly adaptable for use in packaging andother purposes.

Modified embodiments of the invention are shown in FIGURES 8 and 9.These are cross-sections of material taken in the same plane as FIGURE 7but showing alternate modes in which the side walls of the embossments17 may be formed. It was pointed out in connection with FIGURE 7 thatthe side walls 10' of the embossments were sealed substantiallythroughout their extent as shown in that figure. In some cases it may bedesirable to seal only a portion of the side walls and this partialsealing of the side walls is shown at 40 in FIGURE 8. To accomplish thismode of sealing, the pressure effected by the belt 27 in FIGURE 1 isreduced so that the embossments 17 are compressed just enough to bringthe upper edges of the adjoining embossments into contact one with theothers. Under certain conditions, it may be desirable to provide amaterial configuration wherein the side Walls of the embossments 17 aredisposed in close proximity one to the others but are not in effectsealed. A somewhat softer cushioning material is obtained throughoutinitial degrees of compression, though with substantial compression, thewalls do move in contact one with the others. This form of the inventionis shown in FIGURE 9, and it will be observed that a smaller gap existsbetween the side walls 10' of the embossments 17. As in the case of theembodiment shown in FIGURE 8, the structure in FIGURE 9 is obtained byfurther decreasing the pressure effected by the belt 27.

The material in accordance with the invention may be made in continuoussheets of any desired width and is useful for a wide variety ofapplications such as packaging, padding and insulating. In the lattercase, 48" material is particularly adaptable for use in the insulationof walls as the vertical studs are customarily placed on 12-inchcenters. In any event, the material need only be secured with enoughfasteners to prevent it from sagging :or shifting in the course ofinstallation of the inner wall surface. In certain cases, it may bedesirable to puncture those cells overlying each stud to avoid possibledeformation of the wall surface when light wall board is used. Actualobservations have indicated that while insulation between the studs isimportant, a substantial amount of heat will be conducted by the studsso that the utilization of a plastic covering on the studs affords asubstantial improvement in reduction of heat conduction. This preventsloss of heat in the wintertime and also prevents the transfer of heatfrom the outer walls of the structure to the inner walls in thesummertime.

While only certain embodiments of the invention have been illustratedand described, it is apparent that modifications, alterations andchanges may be made without departing from the true scope and spiritthereof as defined by the appended claims.

What is claimed is:

1. An insulative cushioning material comprising a laminate of at leasttwo continuous plastic films, at least one of said plastic films havinga plurality of closely spaced embossments extending from at least onesurface of said laminate, said films being secured one to anotherthroughout the embossment defining areas to form hermetically sealedpockets in said laminate and said ernbossments being joined one toanother throughout contiguous wall portions of adjacent embossments.

2. An insulative cushioning material comprising a laminate of at leasttwo continuous plastic films, at least one of said plastic films havinga plurality of closely spaced embossments extending from at least onesurface of said laminate, said films being secured one to the otherthroughout the embossment defining areas to form hermetically sealedpockets in said laminate and said embossments being joined one toanother throughout contiguous wall portions, the joined contiguous wallportions of said embossments defining relatively flat areas and the topsurfaces of said embossments defining a relatively smooth, continuoussurface in a plane substantially parallel to said other film in saidlaminate.

3. An insulative cushioning material of a unitary structure comprisingtwo substantially smooth and continuous outer layers of plastic disposedin spaced, generally parallel planes and ribs substantiallyperpendicular to said planes dividing the space between said. outerlayers into hermetically sealed cells, and entrapping a fluid therein,said ribs constituting at least two fused layers of plastic.

References Cited UNITED STATES PATENTS 11/1935 Grayson et al. 161-423 XR6/1951 Swayze et al l56-595 XR FOREIGN PATENTS 908,579 10/1962 GreatBritain.

US. Cl. X.R. 161131

